The response of the magnetic ordering of layered cobalt oxide chalcogenides to changes in electron count will be investigated in detail following a preliminary experiment at ISIS. The topotactic deintercalation of coinage metals from Sr2CoO2Cu2Se2, Sr2CoO2Ag2Se2 and Sr2CoO2Cu2Se1.6S0.4 using an iodine solution will produce a series of compounds. The effect of composition on magnetic ordering will enable the robustness of two competing magnetic structures, and the competition between them, to the Co oxidation state to be probed. The combined use of OSIRIS and HRPD for obtaining structural and magnetic information has been shown to be effective for similar compounds.